1. Field of the Invention
The present invention relates to a DNA fragment that contains a gene encoding creatinine amidohydrolase, a recombinant vector containing the said DNA fragment and a transformant containing the said vector. Furthermore, the present invention also relates to a method for producing creatinine amidohydrolase by the use of the said transformant.
2. Description of the Prior Art
Creatinine amidohydrolase (EC 3.5.2.10) is an enzyme that catalyzes the following conversion reaction between creatinine and creatine. ##STR1##
Creatinine amidohydrolase is employed for the measurement of creatinine or creatine in blood serum or urine.
Creatinine amidohydrolase has been produced by cultivating microorganisms with the ability of producing creatinine amidohydrolase, such as Pseudomonas spp., in the presence of creatinine, creatine or a mixture of these two substances, and recovering creatinine amidohydrolase from the culture broth (Amino Acid.cndot. Nucleic Acid, Vol. 35, 39-46, 1977).
However, this method necessitates the addition of costly substances such as creatinine or creatine to the culture medium. Moreover, the yields of creatinine amidohydrolase obtained by this method have not been adequate. Therefore, the development of an efficient method for the production of creatinine amidohydrolase without the use of creatinine or creatine is desirable.